Mode of holding tubes during the operation of drawing them.



H. HIGGIN. MODE OF HOLDING TUBES DURING THE OPERATION OF DRAWING THEM. APPLICATION FILED AUG. 10, mob.

1,025,568. Patented May 7, 1912.

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UNITED STATES PATENT OFFICE.

HENRY HIGGIN, OF NEWPORT, KENTUCKY, ASSIGNOR TO THE HIGGIN MANUFACTUR- ING COMPANY, OF NEWPORT, KENTUCKY, A CORPORATION OF WEST VIRGINIA.

MODE OF HOLDING TUBES DURING THE OPERATION OF DRAWING THEM.

To all whom it may concern:

Be it known that I, HENRY HIceiN, a citizen of the United States, and a resident of the city of Newport, in the county of Campbell and State of Kentucky, have 1nvented certain new and useful Improvements in the Mode of Holding Tubes During the Operation of Drawing Them, of Which the following is a specification.

Heretofore the mode of connecting the grappling mechanism to the tube to be drawn has caused a large loss of material amounting to a large per cent. of the value of the tube itself. I

The object of my invention is to prevent such waste, and to diminish the amount of such loss to a minimum.

The nature of my invention consists in a new and useful mode of forming the end of the tube to be drawn so that the gripping mechanism shall have a good and sufficient hold upon the end portion of the tube, and shall maintain such hold without crushing or in any wise damaging the tube.

In the accompanying drawing making a part of this specification, and in which similar letters of reference indicate corresponding parts,Figure 1 is a view in perspective of the end portion of a tube, where a given proportion of the end has been formed under the first operation or step of my invention. Fig. 2 is 'a perspective view of the same tube showing a portion of said end part as formed by the second operation or step of my invention. Fig. 3 is a side elevation of the part shown in Fig. 2. Fig. 4 is a view in perspective illustrating the injury to the tube, made-by the present method to prepare this end of the tube to receive the gripping device whereby it is directly drawn'forward through the die. This method is commonly known as pointing. Fig. 5 is a longitudinal, central sectional view of a tube whose end is formed according to my invention, and of the plug inserted in the end of the tube, and of thegripping device and of the ball and rod within the tube. Fig. 6 represents a transverse vertical section of the reduced end portion and plug shown in Fig. 5, said section being taken in the plane of the dotted line 6, 6, of Fig. 5. This section Fig. 6 is on a larger scale than that to which Fig. 5 is drawn.

Specification of Letters Patent.

, Application filed August 10, 1908.

Patented May '7, 1912.

Serial No. 447,833.

To those not thoroughly acquainted with the mode of making tubes of less diameter and at the same time thinning them, the

following explanation is due. The primary ect of the operation known as tube drawing is ordinarily to make the tube smooth and handsome. The means employed in drawing arefirsta die. Such a die is shown in Fig. 5. It consists of a metal ring R of suitable conformation. The ring being subject to a great strain, it is necessarily very strong. The ring comprises a large body of metal which is well reinforced. Thus in Fig. 5, R indicates the die having the passage or hole B through it. The die R is fixed to a suitable frame or support. In the present instance, one form of reinforcement is shown, namely: that indicated by the character R T indicates a portion of a tube. The tube is of a diameter slightly larger than the hole R of the die R. Within the tube to the left of the die R, is a ball B of suitable conformation. This ball B is usually provided with a' rod or shank S. By this shank S the ball B is readily located in the tube T just in front of (namely: in Fig. 5 to the left) the die R.

The operation of drawing the tube T consists in drawing it forcibly through the die B. An important function of the ball B is to prevent the tube T from being crushed or put out of its true circular shape as it, the tube,is drawn through the die. The ball B remains in the position shown relative to the die R duringthe operation of drawing the tube. For different tubes of differing diameters which are to be drawn, the diameter of the die R is to be varied according to the product desired. Very commonly a tube is drawn twice. The first drawing reduces the diameter of the tube a given degree, and at the same time thins the metal somewhat. The second operation of drawing is done with a die R of a less diameter than that oft-he die employed in the first'operation of drawing. When the tube has been drawn through the second die, its diameter has been still more diminished,

and the thickness of its metal has been decreased. The diameter of the ball B is also to be varied as occasion requires relative to the diiferent sizes of tubes whose interior surface is to be finished. It. is to be noted that when the inside of the tube is to be polished and made true as well as the outside, the diameter of this ball is greater than when it merely serves to prevent the tube being crushed. By these operations, all of the roughness of the surface of the tube both within it and on the outside of it, and all the inequalities in the surface of the metal have been removed. The tube is now a thing of beauty, and is very attractive. Being perfectly smooth, it can also be employed for a great many important uses in the mechanical and hydraulic, et-c., arts.

In order to draw a tube through the die R, some kind of a device for gripping, grasping or holding on to an end portion of the tube must be employed, and this holding device is connected to a chain or rod which latter is forcibly, at will, drawn away from the die R, and draws the tube outward through the die R. The ordinary device for catching hold of the tube to draw it consists of a gripping device, quite similar to a pair of pincers or forceps or a clutch. It is necessary when the operation of drawing is to be begun that that end of the tube which is to be gripped by the grippers shall project through and beyond the die R in the direction in which the tube is to be drawn. To put this portion of the tube in condition to be passed through the die, the usual Way is to crudely crush it. This crushed portion is then passed into the die, namely: in Fig. 5, to the right of the die. The gripping device is now compressed upon this crushed end portion, and the tube is drawn through the die. In Fig. 4, I have well illustrated this mode of preparing the end of the tube for the gripping device to grasp it. This crushing is irregular, and the shapes which the crushed portion assumes vary more or less with every tube crushed. In this operation of crushing, the crushing is out of the center so that the portion left to be gripped by the grippers causes the grippers to pull the tube a little out of the true line of its axial length. This drawing the tube out of line is obviously conducive to many disadvantages, among which are the waste of power and the undesirable effect upon the tube itself resulting from this incorrect drawing of the tube. This crushed portion is of considerable length. The length of it will be six inches, or more. My invention substitutes for this irregularly crushed portion a symmetrical mode of manufacture of the end of the tube for the grippers to grasp, and whereby the amount of metal used for the gripping device is greatly diminished and at the same time this end of the tube can, as a step preliminary to being grasped by the grippers, be readily passed into and projected beyond the die R, in position for the grippers to take hold of it.

One of the most important parts of my improved mode of manufacture consists in folding in the tubing in planes parallel to the axis of the tube and at substantially regular intervals. This infolding reduces the diameter in a symmetrical manner, and the true longitudinal center of the reduced portion is the axial center of the tube. Consequently when the gripping device is applied to this reduced portion, and grips it and the tube is thereby drawn forward, the pull from the grippers is in the direct axial line of the tube. Hence the drawing is true, and the best results are obtainable. The manufacture of this reduced end portion is preferably accomplished by two operations. The result of the first operation is shown in Fig. 1. The product shows four infoldings of metal, respectively marked A, A, A, A. They are all alike and hence are marked with the same letter. The metal is pressed in from the outer peripheral surface of the tube, on a. line A thereby forming on the inside of the tube, the bead A. Tn this operation, the inwardly extending space 0 formed by the bead and between the opposing adjacent edges, C C of the periphery is yet wide, relatively speaking. By the succeeding operation, this reduced end portion X is still further reduced in size. Each space C, between the opposing adjacent edges C C of the periphery is diminished, and the entire structure correspondingly contracted. Besides this, a shoulder D is formed where the reduced portion begins on the tube. This shoulder is, in part, a result of the making of the surface of the reduced portion X, everywhere parallel to one another and to the axis of the tube. But this shoulder D is gently curved beginning at a point as E, where the tube is of its regular size and ending at the point E This gentle incline enables this end portion of the tube to partly enter the die R, before the operation of drawing begins and thus constitute a preparatory step in the oper ation.

The aforesaid operation results in producing the device, namely: the tube with the point or end Z, shown in Figs. 2 and 3. I also provide a plug H having a portion H adapted to accurately and closely fit within the reduced portion Z, and a head larger than the interior of this reduced portion and therefore prevented from entering said interior. The surface of the part H is formed so as to accurately fit the various shapes (configurations) of the device Z.

ribs H adapted to fit the interior recesses K of the reduced portion Z. This plug H has grooves K which respectively receive This plug H therefore has enlargements or the infolded ridges A of the reduced tube Z. The part H of the plug may be very slightly tapered so as to fit snugly within the reduced end portion Z of the tube. The same plug can be fitted in successive tubes.

In practice, the reduced end portion Z is passed through the die R until the shoulder D interfits the beveled or curved edge of opening R of the die. The part H of the plug H is now inserted in the interior of the reduced portion Z of the tube, as shown in Fig. 5 and in cross section in Fig. 6. The gripping device M is next applied to this reduced end portion Z and forcibly grasps it. The preferred construction of this gripping device M is well known and consists as follows: There is a jaw M and a jaw M These jaws are pivoted together at M The rear ends (not shown) of these jaws are connected to links connected to a single pull or chain, so that when the chain is pulled, the jaws are forcibly brought together and respectively engage the opposite sides of the reduced end portion Z. The plug H prevents this reduced portion from being in anywise crushed. Power being applied, the jaws are moved to the right and the tube is drawn through. the die. Thus the drawing is accomplished, and a large saving in tube material is effected.

Among the other advantages resulting from the use of my invention may be mentioned: In the former mode of reducing the tube (see Fig. 4 for one kind of illustration), it is a common occurrence for the abrupt buckle, one form of which is indicated at P, Fig. 4, to follow back into the tube as it is drawn through thereby often spoiling two to three feet of the tube to the left of Copies of this patent may be obtained for the point P. My invention also prevents frequent slipping of the gripping irons or device off from the reduced end portion W, while the tube is being drawn. Such slipping is not infrequent in the said old meth ods, and is liable to injure the operator as well as to do damage to the machine. The combination of the uniform body resulting from the reductioli of the end portion of the tube as per my invention, and the solid plug constitutes a solid body which prevents the gripping or grappling device from slipping while this end is gripped, and the tube is drawn. I am also enabled to save one half of the waste heretofore made in the usual (former) mode of pointing (reducing) the end portion of the tube for enabling it to be gripped for drawing, and I am enabled to prevent the possibility of the waste from the buckling of the tube back of the reduced portion as heretofore pointed out as a frequent contingent accident following the old method.

What I claim as new, and of my invention and desire to secure by Letters Patent, 1s:-

A tube adapted to be drawn, and having a body portion with an end portion whose periphery is folded into the interior of the tube with more than two shallow folds at regular intervals, and having a coaxial longitudinal opening throughout said end por' tion adapted to receive a plug to support the gripping devices.

HENRY HIGGIN.

Attest:

HENRY A. FABER, HORACE C. DRAKE.

five cents each, by addressing the Commissioner of Patents. Washington, I). 0. 

